wax

casting#materials: wax
casting#techniques: wax

The Lost Wax Technique aka investment casting

Any of various mixtures of long-chain hydrocarbons that solidify at or above room temperature that resemble bee's wax. Recipes, techniques, sources. Wax is another of those materials that is commonly used both as a pattern and as a casting material.

Recipes:
gulf wax
sculpting wax
machinable wax

Techniques:
gluing wax pieces together

foam cores instead of traditional wire armatures. wax expands as it heats up and can crack the investment shell during burn out. Foam collapses as it heats up, so this doesn't happen. *1

Links:
Artmetal forums have a lot of talk about lost wax, for obvious reasons
http://www.artmetal.com/w-agora/bn=techtalk_casting

A pictorial overview of casting a bronze statue.
http://www.whiteriverfoundry.com/makingbirdform/Moldmaking.htm